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9C1

is it the clutch?

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Hey all - a couple times now this has happened and I can't figure it out.  At a complete stop, getting ready to take off (so I'm in first gear), I raise the throttle and go to let the clutch out like normal.  The next part happens all in a split second: as I let the clutch lever out, it's like the bike just barely starts to move but then the revs go jump and it feels like the clutch was pulled back in just for an instant, then immediately the clutch feels like it engages and the bike takes off.  It startles me when it happens so I let off the throttle and pull in the clutch, then I redo the process and the bike takes off normally.  Is this the beginning of a clutch problem?  I have zero problems with the bike otherwise, and every other time I take off it's totally normal.

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I would flush and bleed the hydraulic line first, followed by examining the rod to be sure it is straight and not got anything causing it to hang up. 

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The front sprocket is new (well, new earlier this year).  The hydraulic fluid hasn't been changed by me, and I've owned the bike for almost 2 years (it's got 37k on it).  I can see about flushing the fluid and putting in new.

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Flush and bleed. 

My clutch was giving me some weird feel issues. Engagement was not what I would call "normal" or consistent. 
I vacuum bleed the system with all new fluid and it is like a new bike again. Much better feel and engagement. Actually lower lever effort as well. The old fluid was not low and did not look particularly dark or contaminated but the fresh fluid still did wonders. 

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It sounds like you're saying: While your hand is releasing the clutch in a normal, progressive manner, the resulting "action" of clutch engagement that you're experiencing seems to have something like a sticking-point or hesitation in it, meaning that the clutch movement isn't exactly following the command that your left hand is giving it (something is causing the Clutch Slave Cylinder to "pause" or momentarily stick in place, causing a noticeable slow down as it transits its range of motion during your clutch-lever release).

 

If this is the case I'd say it sounds like the rubber sliding seal inside your bike's Clutch Slave Cylinder has simply lost its ability to slide smoothly along the inside the machined aluminum housing of the Clutch Slave Cylinder barrel.

 

Remove Clutch Slave Cylinder assembly, disassemble, clean all parts, the replace rubber parts and the return spring, reassemble, refill hydraulic fluid, bleed system, ride.

 

 

 

Here's what the Clutch Slave Cylinder looked like on my '99 5th Gen VFR:

DSCF1325_zpsnumdxgn3.jpg

 

DSCF1324_zpsp2iv7fdy.jpg

 

Question: How smoothly do you think the Clutch Slave Cylinder's internal piston was sliding with this 20-year-old brown muddy goo in it?  (Not to mention the fact that the rubber sliding-seal on the Clutch Slave Cylinder's piston was also 20-years-old and pretty much hardened up instead of soft and supple as a rubber seal is meant to be)

 

 

And... this is what I found inside my bike's Clutch Master Cylinder:

DSCF1275_zpsruigbnbr.jpg

 

 

 

Cleaned and refurbished:

DSCF1281_zpsyni3brrl.jpg

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DOT 3 DOT 4 and DOT 5.1 are Glycol based fluids designed to signal
moisture contamination by changing color... the fluid will start to
turn golden, then light brown, then dark brown indicating that it has
absorbed progressively more moisture. Eventually, if left unchanged
beyond the recommended service interval, the fluid will become dark
and yukky, indicating high amounts of water absorption and thus badly
contaminated fluid... user friendly Glycol based fluids also reduce
the effect of both corrosion and compressibility because it is not
only designed to accept significant amounts of moisture, but even to
neutralize it by dispersing this moisture evenly throughout the
system, thus preventing its concentration in any one area...

 

Honda's RC45 employs the same master cylinder as VFR...
attachment.php?attachmentid=515997&stc=1


Moisture Contaminated
attachment.php?attachmentid=515996&stc=1

 

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Really good info you've posted BLS. Seeing it's just so easy to bleed the 8gen non linked system. I replace all the Clutch and Brake fluids every 12months with DOT 4. YMMV.

Cheers.

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Thanks for the feedback.  Looks like I'll start with cleaning out and refurbing the clutch hydraulics. 

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